1. Field of the Invention
The present invention relates to a connector and more specifically, to a connector used for electrically connecting a home, an office or an industrial electronic device and a substrate or substrates in an electronic device.
2. Description of the Related Art
Patent Document 1, for example, discloses a connector including a power source, a signal line, a ground line, a shield line or the like for connecting a substrate and an electronic device or substrates in an electronic device.
In Patent Document 1, it is disclosed a connector for which a circuit substrate in a form of a card edge connector such as a Dual Inline Memory Module (DIMM) or the like composed of plural Dynamic Random Access Memory (DRAM) mounted on a print substrate, is a connecting target.
For the card edge connector, plural pads are aligned on its surfaces with equal intervals in an alignment direction which is perpendicular to an inserting direction through which the card edge connector is inserted. The connector includes plural terminals each including a first contact portion and a second contact portion aligned to correspond to the pads of the card edge connector such that the first contact portion and the second contact portion of each of the terminals push the respective pad when being connected with the card edge connector.
For the connector, the terminal is configured such that the first contact portion touches the respective pad before the second contact portion touches the pad when the card edge connector is inserted into the connector to wipe the surface of the pad with the first contact portion. By this operation, dirt, dust, oxide layers, rust or the like on the surface of the pad can be removed by the first contact portion. Therefore, the electrical contact between the second contact portion and the pad can be ensured.
When inserting the card edge connector into the connector and the first contact portion pushes the pad, a reaction force is generated from the pad toward the first contact portion.
However, in Patent Document 1, as the first contact portion and the second contact portion are formed by peaks of an elongating member composing the terminal formed in a waveform, the force applied to the first contact portion is transmitted to the second contact portion to cause a change in pushing force of the second contact portion toward the pad.
In order to stabilize the pushing force of the second contact portion toward the pad to a predetermined value, a bottom portion between the first contact portion and the second contact portion which is protruding in a direction opposite to the first contact portion and the second contact portion is provided. The bottom portion is positioned to touch a wall of a housing of the connector when the card edge connector is inserted into the connector for retaining the pushing force of the first contact portion and the second contact portion toward the pad.
In this technique, the connector is designed such that a force generated by the reaction force from the pad is compensated by a force generated from the bottom portion which is touched to the wall of the housing to maintain the pushing force of the second contact portion toward the pad to be a predetermined value, when the card edge connector is inserted into the connector.
However, the reaction force from the pad or the force generated from the first contact portion may change to alter the pushing force of the second contact portion. It means that the pushing force of the second contact portion toward the pad depends on the force generated between the first contact portion and the pad.
Therefore, it may become difficult to maintain the pushing force of the second contact portion toward the pad to the predetermined value and so that it is required to improve the reliability in an electrical connection of the connector.
Further, in Patent Document 1, the terminals of the connector are intended to be connected to a substrate of an electronic device, to which the card edge connector is to be electrically connected, with only a surface mount technology (SMT) by solder.
However, recently, connectors which connect an electronic device and a substrate or substrates by a press-fit technology without using solder have been developed and required.